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Date: Sun, 20 May 2001 07:09:57 +0900
Message-ID: <868zjt56tm.wl@cheerful.com>
From: FUJISHIMA Satsuki <sf@FreeBSD.org>
To: FreeBSD-users-jp@jp.freebsd.org
In-Reply-To: <20010519200818D.hino@nwk.cl.nec.co.jp>
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	<20010519200818D.hino@nwk.cl.nec.co.jp>
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Subject: [FreeBSD-users-jp 61629] Re: too slow ata (Re: SOHO PC-RAID10)
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At Sat, 19 May 2001 20:08:18 +0900,
hino@ccm.cl.nec.co.jp wrote:
> $B$^!"%I%i%$%V%Y%s%@$r?.$8$-$l$k?M$@$1(Bwc=1$B$K$7$J$5$$!"(BFreeBSD$B$H$7$F$OA4(B
> $B$F$N(BATA$B%I%i%$%V%Y%s%@$r?.MQ$9$k$3$H$O=PMh$J$$$+$i!"%f!<%6$N%G!<%?$r<i(B
> $B$k$?$a$K!"%G%U%)%k%H$O(Bwc=0$B$H$9$k!"$H$$$&$3$H$G$7$g$&$M!#(B

$B$($(!%7k6I$=$3$K9T$-Ce$/$3$H$K$J$j$^$9$M!%(B
write caching+power failure$B$G$I$&$J$k$+!$$H$$$&$N$r(BIBM$B$N%5%$%H$GC5$7$?(B
$B$N$G$9$,!$$3$s$J$N$,=P$F$-$^$7$?!%(B

http://www.storage.ibm.com/hardsoft/diskdrdl/technolo/writecache/writecache.htm
If an error or power failure occurs, the host software must verify
what is actually written on the disk and take appropriate steps to
rewrite the data as part of the restart process. For most computing
environments, disk errors and power outages are rare. In addition,
many manufacturers are adding battery backup to their computing
systems so that even if a power outage or equipment failure occurs,
decreasing the chance that cached data would be lost.

$B$o$7$,CN$j$?$$$N$O$=$N(Bappropriate steps$B$J$s$8$c$,$N$&!%$H$j$"$($:$3$N(B
$BJ8>O$O!$(BUPS$B$N$J$$IOK3%7%9%F%`$O9M$($F$$$J$$$h$&$G$9!%(B

-- 
FUJISHIMA Satsuki
